1. Field of the Invention:
The present invention relates to an exposure recording apparatus for scanning a recording medium with a light beam from a light source to record an image on the recording medium.
2. Description of the Related Art:
In the art of image recording, there has been used an exposure recording apparatus which records a two-dimensional image on a photosensitive medium mounted on the outer circumferential surface of a drum by rotating the drum about its own axis in a main scanning direction and sweeping a laser beam modulated by image information over the recording medium in an auxiliary scanning direction perpendicular to the main scanning direction.
Different methods are available to record an image at a reduced resolution with the above exposure recording apparatus. According to one method, the size of the spot of the laser beam on the recording medium is increased and the recording pitch in the auxiliary scanning direction is increased. According to another method, the laser beam spot and the recording pitch remain unchanged, and pixels based on the same image information are repeatedly recorded as often as required for the reduced resolution. These methods are reversed for recording an image at an increased resolution with the above exposure recording apparatus.
For increasing or reducing the size of the laser beam spot, it is necessary to actuate a lens in an optical system of the exposure recording apparatus with an actuating mechanism. Therefore, the exposure recording apparatus tends to be large in size, complex in structure, and high in cost. For lowering the resolution by repeatedly recording pixels based on the same image information, the recording speed cannot be increased because the recording pitch is constant in the auxiliary scanning direction.
It is a general object of the present invention to provide an exposure recording apparatus which is of a simple arrangement and capable of easily changing the resolution of an image to be recorded on a recording medium and recording the image efficiently on the recording medium.
An object of the present invention is to provide an exposure recording apparatus which is capable of increasing the speed to record an image when the resolution of the image is lowered.
Another object of the present invention is to provide an exposure recording apparatus which is relatively small in size and low in cost.
Still another object of the present invention is to provide an exposure recording apparatus which is capable of recording an image efficiently on a recording medium even at a high resolution.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative example.